Parallax Image

Recently, I've been seeing this parallax effect being used quite often on Wordpress websites. Let's recreate this subtle parallax effect using React and Motion.

Initializing the project

First, we will be creating our project and installing some packages.

• Let's start with creating our app using NextJS by running npx create-next-app@latest in the terminal.
• Next, for handling the animations we'll install the Motion library by running npm i motion.
• We will be using Lenis scroll to enable smooth scroll animations by running npm i lenis.

Creating the layout

We create a list of images which we'll be using for the project.

const images = [
  {
    name: "London",
    src: "/london.jpg",
  },
  {
    name: "Paris",
    src: "/paris.jpg",
  },
  {
    name: "Tokyo",
    src: "/tokyo.jpg",
  },
];

Next we render the images from the list.

<div className="relative w-full p-4 bg-neutral-50">
  <div className="flex justify-center items-center h-[60vh]">
    <h1 className="text-6xl md:text-9xl font-bold uppercase text-neutral-900">
      Parallax demo
    </h1>
  </div>
  <div className="space-y-4">
    {images &&
      images.map((image, index) => (
        <ParallaxImage key={index} name={image.name} src={image.src} />
      ))}
  </div>
  <div className="h-[60vh]" />
</div>

Animating the Parallax Image

First, we create a ref for the container of the image. We'll set it as the target for the useScroll hook from Motion to track its vertical progress within the viewport.

Next, we specify the offset. It describes the points in which the target intersects with the viewport.

const ref = useRef();
const { scrollYProgress } = useScroll({
  target: ref,
  offset: ["start end", "end start"],
});

• "start end" means the intersection in which the top ("start") of the target element meets the bottom ("end") of the viewport. It describes the place where the element first enters the screen.
• "end start" means the intersection in which the bottom ("end") of the target meets the top ("start") of the viewport. It's the place where the target element leaves the screen.
• The scrollYProgress value ranges from 0 to 1 with "0" being the moment the target element first enters the viewport and "1" the moment right before the element leaves the viewport.

With the useTransform hook from Motion we can transform the scrollYProgress values into other motion values.

const imageY = useTransform(scrollYProgress, [0, 1], ["-250px", "0px"]);
const textY = useTransform(scrollYProgress, [0, 1], ["0px", "-250px"]);

• The value for imageY will be -250 pixels when the value for scrollYProgress is at "0" and 0 pixels when the value of scrollYProgress is at "1". The hook will take care of all the values in between these two numbers. This means the image will be shifted down by -250 pixels when it first enters the viewport and it will move up as the user continues to scroll down.
• We do the opposite for textY to create a second layer for the parallax effect.

Let's put it all together and create the component.

function ParallaxImage({ name, src, index }) {
  const ref = useRef();
  const { scrollYProgress } = useScroll({
    target: ref,
    offset: ["start end", "end start"],
  });

  const imageY = useTransform(scrollYProgress, [0, 1], ["-250px", "0px"]);
  const textY = useTransform(scrollYProgress, [0, 1], ["0px", "-250px"]);

  return (
    <div
      className="relative rounded-2xl overflow-hidden h-screen"
      key={index}
      ref={ref}
    >
      <motion.img
        src={src}
        alt="image"
        className="object-cover w-full h-[125%] brightness-75 object-top"
        style={{ y: imageY }}
      />
      <motion.h1
        style={{ y: textY }}
        className="text-6xl md:text-[12rem] font-bold uppercase place-self-center absolute top-1/2 left-1/2 transform -translate-x-1/2 translate-y-1/2 "
      >
        {name}
      </motion.h1>
    </div>
  );
}

• To apply the animation to an element, we have to change it to a motion component. <img> turns into <motion.img> and <h1> turns into <motion.h1>. We can then access the style and customize it with our motion value.

style = {{ y: imageY }}

The end result will look like this: